Metalworking of cast metal articles such as prosthetic knee implants typically requires surface finishing such as buffing, polishing, deburring, grinding and satin finishing. Traditionally, these finishing steps were performed by hand. More recently, however, automated processing replaced most manual operations. As compared to manual finishing, automated finishing provides greater efficiency, precision, and safety.
An important aspect of robotic finishing knee implants is the need to manipulate the implant to expose all surfaces to a finishing device such as a wheel or belt. To accomplish this, the implant must be held by the robot and maneuvered to various orientations relative to the finishing device. Importantly, the robot must hold the implant against the finishing device with pressure yet not mar the surface of the implant when picking it up or putting it down.
One technique for enabling a knee implant to be picked up and manipulated by a robot in a finishing operation is to mount the knee implant to a metal support bar. In this technique, the knee implant is fixed to a central region of a metal bar through the use of fasteners such as screws. The bar laterally extends beyond the both outboard edges of the knee implant to provide two graspable handles for the robot. The robot may then use jaws to clamp onto one handle of the bar and manipulate the knee implant relative to the finishing device. The knee implant and bar assembly may then be set down while the robot repositions its jaws to the other graspable handle of the bar. The knee implant may then be further manipulated relative to the finishing device.
While the use of support bars for finishing knee implants has been widely accepted, there is room for improvement in the art. For example, each knee implant must be fixed to a dedicated support bar by way of fasteners such as screws. This is a labor intensive process. Also, one support bar must be provided for every knee implant in a particular batch to be finished. Assuming that twelve knee implants are provided in each batch and finishing operations continue throughout the various working shifts, a large number of bars must be kept in stock. Also, since the finishing process wears the support bars, each support bar must be periodically replaced. Given the large number of bars in a typical inventory, this can be expensive.
In view of the forgoing, it would be desirable to provide a tooling system for enabling the direct clamping of knee implants to thereby eliminate the need for support bars.